Can someone please help me

(b) 7.8 degrees

Step-by-step explanation: You need to pay attention to the number -8.4. It says the temperature changed by +2.7 degrees an hour for 6 HOURS. Therefore, your equation would be -8.4 + (2.7 * 6).

You have to solve whats in the parenthesis first, so your equation would end up being -8.4 + 16.2 making your answer 7.8 degrees.

last option

step-by-step explanation:

given that δdef is right and isoceles,

assuming that side df is the hypotenuse means that de an ef are the other 2 sides that intersect at 90° and are of equal length.

because they are of equal length, we can say that they are congruent

because they intersect at 90°, their slopes must be opposite reciprocals.

only the last option satisfies these conditions.